Yes, slugs eat brunnera but only in small amounts on the soft new spring leaves. Once the leaves get tough and hairy, slugs lose all interest in the plant. The NC State Extension calls them occasional visitors that cause no real harm to mature plants. You will see some bite marks each spring but nothing too bad.
Brunnera slug resistant traits kick in once the leaves reach full size each spring. The mature leaves have a rough, hairy texture that slugs do not like to crawl across. The tiny stiff hairs poke into the slug's soft body. This makes brunnera one of the better choices for slug prone shade beds in your yard.
I have grown hostas and brunnera in the same shade bed for many years now. In wet springs, my hostas get chewed to lace by slugs while my brunnera stays mostly fine. The hostas have soft, smooth leaves that slugs love. The brunnera leaves are rough and tough by the time slugs are active in big numbers.
The one weak point comes in early spring with the soft new shoots. When I first see brunnera leaves push up from the soil in March, they are soft and bright green. These tender leaves can take some slug damage on cool, damp nights. The damage shows up as small ragged holes in the new growth.
Slug damage shade plants face is worse in wet, cool springs than in dry years. Slugs need moist soil to move around and feed each night. In dry springs, slug numbers drop and your brunnera will look great with no help from you. Watch the weather to plan your slug control timing each year.
For brunnera pest control, I lean on a few easy tricks that work well for me. Iron phosphate bait is my top pick for slug control these days. The bait is safe for pets, kids, and birds in the yard. Sprinkle it around your plants in March when the new leaves push up. One small handful per plant works well in most beds.
Beer traps also work well if you do not mind the gross cleanup task. Bury a low cup at soil level and fill it with cheap beer. Slugs crawl in and drown by the dozens each night. Empty the trap every few days during peak slug season. I always set traps near my new brunnera plants in early spring.
Hand picking at night works great if you have just a few plants to check. Take a flashlight out around 9 or 10 PM on a damp night. You will find big slugs on the leaves and soil. Drop them in soapy water to kill them fast. One or two nights of picking can clear most of the slugs from a small bed.
Copper tape barriers around clumps work as a long term fix for tough cases. Slugs get a tiny shock when they touch the copper and turn back. Wrap the tape around the base of each clump in early spring. The tape lasts for two or three years before it needs to be replaced.
Mature brunnera plants need almost no slug control at all in most years. The rough leaves protect the plant on their own once full size is reached. Save your slug control work for the first few weeks of spring each year. After that, your plants will be slug resistant on their own with no fuss from you.
Read the full article: Brunnera Plant Growing and Care Guide
